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1994 Olds Ciera needs new evaporator

Hi all,
My daughter is getting her learner's permit, so we bought a cheap car for her to learn to drive. Found a '94 Olds Ciera with the 3100 engine for $100. It BARELY ran, but had new tires on the front and appeared to be in decent shape otherwise, so I bought it. Turned out there was basically no fuel pressure. I diagnosed a bad fuel pump, replaced it and she's running great now! I drained and flushed the radiator, and am currently running some cleaner in there to get rid of some gunk that was floating around. The antifreeze was sort of brownish, so no idea how long it's been since it had fresh antifreeze.

Anyway, amongst the other things I discovered the AC was inop. I don't have the gauge and vacuum pump to do the job, so I brought it to a local mechanic. They charged it up and it blew nice and cold for them, but by the time I got it picked up...nothing. On the third trip back to the shop they finally found a leak in the evaporator core, and quoted $675 to do the fix. Um...no.

I'm pretty sure I can get the parts for ~$130 or so, and replace them myself. So the question is: what's the best way to remove/replace the evaporator? Go in through the dash, or from the engine bay? I'll also replace all the o-rings, accumulator, orifice tube etc, but the evaporator doesn't look like a fun task.

I am going to make a suggestion in the brown sludge or any material in the radiator . Look up intake manifold gaskets for that motor or really any gm motor from 92-2004 . I would look to invest into them since you picked it up for cheap basically the coolant leaks into the oil and mixes . You can get a brown mixture out of this . It's not terrible to do but as it's for your daughter I would do it cause she will overheat that over time and cause other issues . Parts for that can be really low or hi depends on how far you wanna go cause its the whole cooling system all hoses even heater core as well . Since your tackling the evap core it might open up some more room to tackle both jobs . They make a Felpro gasket set now that corrects it . jooe this helps us as a forum is always welcome for support or tips to help out

Thanks Keith. The intake gasket replacement is already on the list, but I wanted to flush what I can before I get in there and do that. I've done the replacement on a couple other cars so I know I can get it done in a few hours if everything goes well. I'm also keeping an eye on the oil to make sure I don't have coolant going the other way from a head gasket. I'd hate to to the intake and then have to go back in a few weeks later to do the heads as well.

Although, if the evaporator comes out through the firewall, then a top end refresh would make it MUCH easier to get in there!

Honestly whwt I would do is this get a compression test done first . If all comes back good then bang out the intake manifold gasket almost 9-10 it's the intake manifold gasket and the head gasket is always good . Once it's over heated the heads warp and gasket blows . Usually the rear head gasket goes out or both at once . But would throw a 180 thermostat in it for now you kinda need help programming the car to adjust the fans cooler but at least the thermostat opens up early enough I have seen 200 then a 195 stock thermostat open up and that's way to hot basically the verge of overheating . So if you do plan to do the intake gasket just refresh the whole engine bay for cheap cost and have a reliable car without any issues . Keep in mine the l82 94-6 3100 is a tough little engine but also heads from a newer 3100-3400 and upper and lower intake manifold can put out on for some extra oomph . If your in a emission state they make a adapter for the egr to hook up to . But over all it's peppy for the weight of it https://i.imgur.com/6kighT9.jpg that's mine a 95 century same motor

Ditto on the LIM gasket; make sure you get the metal LIM gaskets. I've got two of these cars with the same engine, a '95 and a '96. The plastic gasket is a ticking time bomb. If the car is cherry, IMHO forget the flush, spring for a new radiator...the cores on the new radiators are about 80% larger than stock. An easy cooling upgrade and you won't have to worry about programming the computer....although I would recommend that as well since GM programming won't flip on the cooling fans unless the AC is running or the engine temp hits 220 F or so. It's just that computer re-flash for these cars isn't something you can go to your local Wal-Mart to have done. You have to find someone who can do it, or make the investment in the equipment (which isn't crazy, but, significant). David Allen has a cool video on YouTube on how to do it yourself.

$675 for an evaporator replacement isn't bad. I paid $1,000, but had I done it over again I would have done it myself.

Just for giggles I asked the local stealership what they would charge....$950 or so. I did get them to tell me that it comes out into the engine bay, so at least I don't have to tear the dash apart. I'm not as bendy as I used to be! According them, the only thing that needs to be removed on the engine is the alternator, so it must not be too bad! I have to finish a refresh on my '84 Goldwing before I can get the Olds into the shop, so it's gonna be a little while.
I'll keep you guys posted.

Well alternator , coils and ignition control modular and bracket The blower motor has to go as well . The bottom 6-8 bolts trust me you will be cursing plus the fact to get to the lower coupling underneath the master cylinder u can see with a light but by get a wrench in there . I would take the ac line hose from the dryer and take that along with the evaporator coil so u can separate them out of the car .

Just for giggles I asked the local stealership what they would charge....$950 or so. I did get them to tell me that it comes out into the engine bay, so at least I don't have to tear the dash apart. I'm not as bendy as I used to be! According them, the only thing that needs to be removed on the engine is the alternator, so it must not be too bad! I have to finish a refresh on my '84 Goldwing before I can get the Olds into the shop, so it's gonna be a little while.
I'll keep you guys posted.

That's what they did on mine, and like Keith says, the coil pack will go too. I saw the witness marks on my plug wires when I did my LIM job last year. They'll also remove the dogbone to tip the motor forward a bit. Confirmed, no ripping out (or ripping up) the dash.

As messy as it gets when applying all back together seal it with black rtv along the otter cover and put it on and line up bolt holes . Please be very careful the hvac coil sits on top of the cover remove the wire harness and two 7-8mm bolts and pull straight out and set aside and don't bang it . As u take the blower motor off grab a shop ac once you pull the hvac resistor use a that opening as a window to get all the leaves out cause once open it up it will fall over the engine . Leaves will fall in places u can't see and start a hot fire mess after u did all your days work and fire her up and get really mad so don't skimp on details my friend . One thing I saw on you pictures is the front valve cover leaking or the pvc grommet leaking oil since they are shinny aluminum valve covers . Since u will have her all apart u can tackle a lot as u repair . Hope it helps keith . The coil bracket is 10mm bolts up front and 12-13 in the rear total of 4

Some time ago I bought a '93 Ciera cheap for son to use for school and work. Unlike the 3100 engine in your '94, the '93 has a 3300 supplying power. Other than that, I presume it's the same basic layout in the engine bay. Last summer, I disassembled and began rebuilding the inoperative a/c system. Getting the evaporator coil cover off was hard due to poor access to the bottom three screws securing the cover to the firewall. Using a pry bar, I was able bend/flex the thin metal exhaust manifold heat shield in front of the cover to provide more room to access those hard-to-reach screw heads.

Since all my '93 Ciera makeover pics got nuked recently by Photobucket, I'm trying Imgur here for the first time.

Evaporator coil cover removed; note location of bottom drain hole and holes and slots for fasteners. I used a 1/4" drive manual ratchet and a Milwaukee battery-powered 3/8" drive ratchet with 1/4" adapter to turn a socket on the screw heads.

Close-up of debris obstructing air flow: bugs, dirt, hair, leaf bits and stems, pine needles, tiny pebbles, etc., all fallen through the air intake in the cowl.

Back side of OEM evaporator coil has wraparound filter element attached with plastic cross-shaped push-in pins. I washed and reused the filter element with the new evaporator coil.

More debris in the evaporator coil space.

I vacuumed up all the debris and cleaned the evaporator coil cover. I also disinfected the evaporator space to eliminate any mold. I made up a bleach solution and used a spray bottle to apply it. After allowing the solution to sit for some minutes, I used a small sponge and clean rinse water to wipe the evaporator space clean before letting it dry.

I'm currently in the process of uploading pics of my a/c system rebuild to my '93 Ciera makeover project thread in the A-body.net forum's Project Central section. If you're interested, check back soon for more detail on evaporator removal and installation.

Question for Imgur users: how do I get my posted image links bring images up automatically for viewing without having to click on the links themselves?

Answer/updated 8/15/2017: click on the desired image uploaded to Imgur, select the "BBC Code (Forums) option and click on "copy", then paste to post intended for A-body.net. Works !!! Thank-you Duke George V for your tips !

There was no deterioration to the OEM filter, so I reused it. I washed the filter in a bucket containing hot water and some Ajax dish detergent, rinsed, and let it dry before reinstalling it. Good as new!

Hi all,
My daughter is getting her learner's permit, so we bought a cheap car for her to learn to drive. Found a '94 Olds Ciera with the 3100 engine for $100. It BARELY ran, but had new tires on the front and appeared to be in decent shape otherwise, so I bought it. Turned out there was basically no fuel pressure. I diagnosed a bad fuel pump, replaced it and she's running great now! I drained and flushed the radiator, and am currently running some cleaner in there to get rid of some gunk that was floating around. The antifreeze was sort of brownish, so no idea how long it's been since it had fresh antifreeze.

Anyway, amongst the other things I discovered the AC was inop. I don't have the gauge and vacuum pump to do the job, so I brought it to a local mechanic. They charged it up and it blew nice and cold for them, but by the time I got it picked up...nothing. On the third trip back to the shop they finally found a leak in the evaporator core, and quoted $675 to do the fix. Um...no.

I'm pretty sure I can get the parts for ~$130 or so, and replace them myself. So the question is: what's the best way to remove/replace the evaporator? Go in through the dash, or from the engine bay? I'll also replace all the o-rings, accumulator, orifice tube etc, but the evaporator doesn't look like a fun task.

Thanks in advance for the help!

GH

Hi, I've done that job several times with varying levels of difficulty. It seems that the larger the car's engine the worse the evaporator core job will be. I haven't worked on the newer cars and haven't done an evaporator on a 3100 car, so your experience may be a little different.

First thing I would do is be sure the evaporator core is actually bad. There are many more likely leak points. I would isolate the evaporator by capping off the lines, and see if it will hold vacuum or air pressure overnight.

It seems the cars I have found leaking were from the rust belt areas, where road salt gets in the evaporator housing, along with dirt dust and leaves etc. This makes a constantly wet, corrosive environment that pits and corrodes the evaporator core.

The evaporator core is done from under the hood. It is not accessible from inside the car. There is a housing over the core, which also holds the blower motor. That housing comes off and the evaporator core is right there.

This video was of a diesel car evap core job. The diesel is very much worse than the others because of the extra insulation. Yours shouldn't be that bad, but the basic job will be similar. My sound is not working on my computer. I don't remember exactly what I said in this video, so it may only be partially relevant. But you can see the job in progress.